Prioritize on demand Schedule Builds over Auto

Auto-Built Schedules get caught in a queue until SchedMan can finish building them all. If a $SCHEDULE:BUILD event (or a $JOB:ADD for a Container Job which queues up a Schedule Build for the Sub-Schedule) takes place while the auto-build Schedules are still in queue the new requests are placed at the end of the queue. This could cause large delays in those dynamically added Schedules being built.

We should create a configurable setting allowing OpCon Administrators to prioritize dynamic or manual build requests over (or under) auto-build requests.